John 5:30

I can of myself do nothing: as I hear, I judge: and my judgment is righteous; because I seek not mine own will, but the will of him that sent me. If I bear witness of myself, my witness is not true.

Here Jesus changed his approach to the closed minds of the priests, still trying to induce them to believe.

I can of myself do nothing ... These words have a double application: (1) I see that nothing I can say will have any weight with you, and (2) my signs should be interpreted by you as revealing that myself alone, apart from God, could never have done such a thing as cure the invalid.

My judgment is righteous ... is the equivalent of "My witness of myself is absolutely true, because I am doing the will of God who sent me."

If I bear witness of myself, my witness is not true ... This means, "But you are rejecting my witness of myself because I am the one witnessing." It is as if Jesus had said, "Oh yes, I read what you are thinking, namely, that if I bear witness of myself, my witness is not true." Thus this verse is a line of the conversation which the Pharisees did not utter, but which Jesus read out of their hearts. Without for a moment yielding any of the authority of his own witness, the Lord immediately marshaled other witnesses. It is as if he said, "Well, all right, since you reject my witness because I gave it, we shall call other witnesses. The first to be called was God himself. See under John 8:13.